Phase formation and evolution, texturing and current transport in Ag/Bi2212 PIT monofilamentary tapes

Superconducting tapes of ceramic material capable of transporting high current densities at high operation temperatures have been revealed as promising conductors in applied superconductivity. Tapes of Ag/Bi2212 present excellent characteristics and their processing techniques are being improved. This work presents a study on the formation of phases and the texturing behavior of Ag/Bi2212 monofilamentary tapes after several heat treatments with different cooling rates from 890/spl deg/C to 830/spl deg/C and silver doping, allowing an optimization of the heat treatment profiles aiming the obtainment of close to stoichiometric superconducting phases with high texturing. The tapes were fabricated using Bi2212 precursor powder and the powder-in-tube (PIT) method. The powder was pressed inside the Ag tube, and the set was mechanically deformed by swaging and rolling to the final thickness of 150 /spl mu/m. After heat treatment, the samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectrometer (EDS). The results show the effect of each heat treatment profile on the microstructure and superconducting characteristics of the Ag/Bi2212 tapes, as well as they show the ways to obtain the best texturing of the samples aiming high current transport.